It is a known problem that electromagnetic interference can occur in lamps between so-called lamp lines on the one hand and mains and control lines on the other hand. In this case, lamp lines provide the electrical connection between an electronic ballast and at least one lighting means. The power for operation of the lighting means is transmitted on this connection from the electronic ballast to the lighting means. A signal at a high alternating or constant frequency is frequently chosen for transmission. In one exemplary embodiment, this is a square-wave signal at a frequency between 10 and 100 kHz.
Mains lines run between a mains connection and the electronic ballast. Control lines transmit control signals for communication with sensors, other lamps or central control units. Depending on the arrangement of the electronic ballast in the lamp, it is also possible for lamp lines on the one hand and mains and control lines on the other hand to run parallel, at least in places. Particularly when wiring is passed to other lamps, the lamp lines and mains and control lines even run predominantly parallel.
The fields around the lamp lines are in this case sufficiently strong to have a negative influence on the EMC behavior of the lamp, because of coupling mechanisms between lamp lines on the one hand and mains and control lines on the other hand. In this case, the lamp line acts as a transmitter, and the mains and control lines act as receivers. In this case, the filter which is normally installed in an electronic ballast can be bridged by this coupling. Electromagnetic interference can be fed in this way into widely distributed mains systems, and can interfere with other equipment.
In order to avoid such electromagnetic interference, lamp lines on the one hand and mains and control lines on the other hand are physically separated as far as possible from one another in the lamp body, in order to keep capacitive and inductive couplings as small as possible. Brackets, curved metal lugs or adhesive points are used for this purpose in the prior art.